Dublin Central byelection candidate Daniel Ennis has issued a legal threat to one-time presidential hopeful Nick Delahanty over social media posts which he says are a smear designed to cause “maximum reputational damage” before Friday’s vote.Nick Delahanty – an online commentator who unsuccessfully sought endorsements from local authorities to contest last year’s presidential election – published a series of posts about Ennis which lawyers for the Social Democrats councillor say are “malicious and grossly defamatory”.Ennis is expected to be in the running to take the seat vacated by former minister for finance Paschal Donohoe. In legal correspondence sent to Delahanty on Saturday, solicitors acting for Ennis said the posts sought to damage his reputation “through baseless innuendo of wrongdoing”. Nick Delahanty addressing councillors in Kerry while seeking their nomination to contest last year's presidential election. Photograph: Kerry County Council livestream The posts, which were still online on Sunday afternoon, sought to link Ennis with an individual who Delahanty claimed acts as a director of several companies providing accommodation to asylum seekers. This individual is also named as a “presenter” on company registration documents for a firm where Ennis was formerly company secretary. In the legal letter, Ennis’s lawyers outline that this function does not mean the presenter is part of a business being registered, and that the individual in question runs a company which assists new firms in filing paperwork with the Companies Registration Office.His solicitors argue that the posts are an attempt to create an impression of a business relationship between this person and Ennis. They say Delahanty’s posts suggest something has been discovered which links Ennis to self-enrichment and having behaved unethically, which they describe as a “slur” and “false and untrue and clearly defamatory”. They also say that another post by Delahanty, which claimed Ennis was “at fault” for not disclosing his position as secretary of a company when elected as a Dublin city councillor, was a “falsehood” as he was not required to do so. The legal correspondence says the posts “are clearly designed to cause maximum reputational damage in the lead up to the Dublin Central byelection”. In a statement on Sunday, Ennis said the posts had resulted in “huge anxiety for my family to the point where my mother was abused on the street yesterday”. “I am absolutely going to defend myself against these smears and call them out for what they are – completely fabricated.”In a statement, Delahanty confirmed he had received the correspondence, was taking legal advice and would not be commenting in detail. He said his posts concerned matters of “clear public interest” and related to public records, company filings, corporate ownership structures and “scrutiny of an election candidate seeking public office”.“I reject any suggestion that I acted maliciously or knowingly published false information,” he said, adding that he did not allege Ennis had committed a criminal offence, acted corruptly or peronsonally profited. Ennis is demanding that Delahanty post a full and unequivocal apology pinned to the top of his X account, not make any further defamatory statements and provide written undertakings that the allegations will not be repeated. It comes as candidates in the Dublin Central and Galway West byelections prepare for an intensive run-in to Friday’s votes. Polls suggest Ennis is slightly behind the Sinn Féin candidate, Janice Boylan, in the capital, while Fine Gael’s Sean Kyne holds a narrow lead over Independent Ireland’s Noel Thomas in Galway West, ahead of centre left candidates led by Labour’s Helen Ogbu. Transfers of lower preference votes will decide who fills the vacant Dáil seats, with counts in both constituencies taking place next Saturday.